It is widely known that there exists an apparatus that prevents a vehicle from stealing by not allowing an engine to work when a theft signal is received from an anti-theft service center (For example, JP-A-2002-59812).
However, it can be foreseen that the apparatus using a prior art cannot appropriately enforce the expected functionality of preventing the vehicle from stealing when the apparatus itself is removed from the vehicle, that is, it cannot receive the theft signal from the anti-theft service center in order not to allow the engine to start.
In view of the foregoing problem, the anti-theft system of the present invention is aimed at providing a system that appropriately prevents the object with onboard devices such as a vehicle from stealing by steeply decreasing/deteriorating the motivation of theft.